science Flashcards
What is the atom’s identity?
The atom’s identity is determined by its atomic number, which is the number of protons in its nucleus.
How is the mass of an atom determined?
The mass is determined by the number of protons and neutrons in the nucleus.
How is the charge of an atom determined?
The charge is determined by the difference between the number of protons (positive) and electrons (negative). Equal numbers = neutral charge.
How do the “boxes” on the Periodic Table of Elements communicate relevant information about elements?
Each box shows the element’s name, symbol, atomic number, and atomic mass.
What are isotopes?
Isotopes are atoms of the same element with the same number of protons but a different number of neutrons.
How would you write the name of an isotope of carbon if it has 6 protons and 7 neutrons?
It would be called Carbon-13 (6 protons + 7 neutrons = 13).
How are isotopes different from one another?
isotopes have the same protons but different numbers of neutrons and different masses.
what are the rules that determine ionic bonds?
Ionic bonds form when one atom gives away electrons (becomes positive) and another takes electrons (becomes negative). Opposite charges attract, holding them together gives electrons to nonmetals
What are the rules that determine covalent bonds?
when two nonmetal atoms share electrons to fill their outer shells
why do metals lose their outer electrons so easily
Metals tend to lose their outer electrons easily because those electrons aren’t held tightly.
What is a metallic bond?
positive metal ions bond to free moving electrons around them, the electrons are free moving because metals easily lose their outer electrons
Why are metals good conductors of electricity?
: Metals are good conductors of electricity because their free-moving electrons can carry electric charge easily through the metal. These electrons can flow when electricity is applied.
what does the law of conservation matter state
all equations must be balanced
What is a Synthesis reaction?
two molecules combine into a single thing, there is one product on the other side of the arrow
What is a Decomposition reaction?
In a decomposition reaction, one substance breaks down into two or more simpler substances. 2H₂O → 2H₂ + O₂
What is a Single Replacement reaction?
In a single replacement reaction, one element replaces another in a compound, remember Jenny Bob and Paul. Zn + CuSO₄ → ZnSO₄ + Cu, one element is left single.
what are ions
atoms with a charge
What is a Double Replacement reaction?
In a double replacement reaction, the positive and negative parts of two compounds swap places. NaCl + AgNO₃ → NaNO₃ + AgCl, think of it like a double date but they switch people.
What is a Combustion reaction?
In a combustion reaction, a substance combines with oxygen and releases energy in the form of heat and light (usually burning). CH₄ + 2O₂ → CO₂ + 2H₂O, two things end up on the products side.
isotope
when an element has a different number of neutrons therefore, has a different mass, it is called an isotope.
rows
horizontal, called periods, each period adds a new electron shell
columns
called families, they react similarly if they r in the same fam. each fam has its own traits
valence electrons
ultimately the reason for bonds , the electrons in the outermost shell of the atom.
